Thousands of users worldwide reported problems with Microsoft 365 apps and services to Downdetector.com, a website that tracks service disruptions.

"We're investigating an issue impacting users' ability to access various Microsoft 365 apps and services," Microsoft 365 Status said on X early Friday.

On its status page for Azure, Microsoft's cloud computing platform, the company said the issue began just before 10 pm ET Thursday, affecting systems across the central US. In an update, Microsoft said it had determined the cause and was working to restore access to its users.

Many global institutions, including central banks, media outlets, and airlines, have experienced a massive IT outage. In the US state of Alaska, emergency services have been affected, and several airlines have grounded their flights worldwide.

Sky News UK was ultimately off air due to the issues, and Australia, which has been particularly hard hit, has seen broadcast networks struggling as systems failed. Supermarkets in both countries have also been severely impacted.

However, a Microsoft spokesperson told the BBC that most services were recovered hours earlier.

A spokesperson for Australia's Home Affairs Minister said the outage seems to be related to an issue at global cybersecurity firm Crowdstrike. The country's cybersecurity watchdog stated no information suggests it was an attack. They mentioned that the outage was due to a technical issue with third-party software used by affected companies.

Alaskan officials reported that many 911 and non-emergency call centres are not working correctly. United, Delta, and American Airlines, all based in the US, have issued a "global ground stop" on all their flights. Virgin Australia and Jetstar have also had to delay or cancel flights in Australia.

Australian telecom firm Telstra said that triple-0 call centres, the primary emergency contact in Australia, are not affected, but they are working with other state emergency services to implement backup processes.